The invention refers to an introducing device for inserting instruments, for example, laparascopic and laparatomic instruments, into a living body.
From German Patent 40 02 235, an introducing device is known for the percutaneous introduction of an endoscope. A housing includes a slide having an opening adapted to be made flush with a channel through which a trocar is passed. The body is punctured with the trocar projecting from the trocar pipe, whereafter the introduction device is pushed up to the housing. Then, the trocar is removed and gas is simultaneously introduced into the body through the trocar pipe. After the withdrawal of the trocar, a spring means pushes the slide is pushed into the closed position in which it closes the channel. Thereby, the channel is sealed from the environment. For a later insertion of an instrument through the housing and the trocar pipe into the body, the closing slide is manually moved into the opened position.
Instruments for insertion into the body via a trocar pipe may differ in diameter. In order to maintain the sealing, it is presently required to set reducing sleeves into the trocar pipe, which is troublesome and time consuming.
From U.S. Pat. No. 4,112,932, an introducing device with a trocar pipe is known, having two discs as a housing that are rotatable relative to each other about a common axis. The disc adjacent the trocar pipe has an opening and the other disc is provided with a ring of passage openings of equal size. Nozzles of equal diameter that are closed by rubber caps, respectively, branch from the passage openings. Each rubber cap is formed with a hole. For the adaptation to the size of an instrument to be used, a rubber cap with a matching hole size has to be selected. This device is complicated to handle. Since there is no closed housing, problems with sterility arise.
Patent Application WO 92/14414 describes an introducing device wherein an adjusting member is rotatably or slidably arranged within a housing and has a plurality of passage openings of different diameters that are selectively adjustable with respect to the openings of the housing for the sealed passage of an instrument. Thus, a passage opening of fitting size may be selected for every trocar or instrument, yet a larger number of passage openings of different sizes require very complex slide structures that are hard to realize.
It is an object of the present invention to provide an introducing device that is simple to handle and allows for a fast adaptation to instruments of different cross-sectional size.